Hello, With kernel 3.14.5... $ sudo umount /mnt/net/alpha/11 umount: /mnt/net/alpha/11: not mounted $ sudo mount -o inode_cache,space_cache,compress=lzo,noatime,nossd,skip_balance /dev/nbd11 /mnt/net/alpha/11 $ sudo mount | grep nbd11 /dev/nbd11 on /mnt/net/alpha/11 type btrfs (rw,noatime,compress=lzo,ssd,space_cache,inode_cache,skip_balance) $ dmesg | tail ... [1353819.363462] BTRFS: device fsid 8cf8eff9-fd5a-4b6f-bb85-3f2df2f63c99 devid 1 transid 25041 /dev/nbd11 [1353819.364668] BTRFS info (device nbd11): enabling inode map caching [1353819.364674] BTRFS info (device nbd11): disk space caching is enabled [1353821.784617] BTRFS: detected SSD devices, enabling SSD mode -- I'm certain the "nossd" option used to work (prevent the SSD mode) with this exact same configuration on older kernels. Any idea why it doesn't now? -- With respect, Roman